Field of the Invention
The present invention relates to a thermoelectric device having a flow channel, through which a first fluid can flow, whereby the flow channel has first walls and side walls connecting the first walls, whereby at least one first wall is in thermal contact with a thermoelectric module. In addition, the invention relates to an arrangement of a thermoelectric device in a heat exchanger.
Description of the Background Art
In motor vehicles a major part of the energy stored in fuel is converted to heat. Apart from being used for heating the interior, for example, the heat is also released partially unused via the exhaust gas.
This has a negative influence on the overall efficiency of the vehicle. In order to increase the efficiency and thereby to reduce CO2 emissions during operation, it is worthwhile to make the energy bound in the exhaust gas utilizable.
The use of thermoelectric devices is necessary to achieve this. These thermoelectric devices have thermoelectrically active materials, which allow the generation of electrical energy. To this end, the thermoelectric materials at their interfaces, and thereby preferably at two opposite interfaces, are exposed to a temperature difference.
The exhaust gas which flows through the exhaust gas line lends itself as a hot source particularly in motor vehicles. The exhaust gas temperature are sufficiently high over the entire exhaust gas line, so that a thermoelectric device can be integrated at various locations in the exhaust gas line.
A coolant stream of the vehicle, for example, lends itself for a cold source. For this purpose, either an already present coolant circuit can be expanded, or if necessary an additional circuit can be integrated.
The publications EP 1230475 B1 (which corresponds to U.S. Pat. No. 6,474,060), EP 1475532 A2 (which corresponds to U.S. Pat. No. 7,100,369), WO 2007026432, JP 10281015AA, JP 2000282960AA, JP 2004068608AA, JP 2005083251AA, or JP 2005117836AA disclose approaches by using such a thermoelectric device; however, these implementations are less efficient because of the disadvantageous connection of the thermoelectric elements to a heat exchanger.
To assure an especially efficient use of a thermoelectric device, it is very important that the individual thermoelectric elements are thermally connected especially advantageously to the fluids. In particular, a low heat transfer coefficient is advantageous to be able to produce the maximum benefit from the temperature difference of the two fluids, or in an alternative design to realize the most effective heat pump possible with as low a current consumption as possible.
At present particularly disadvantageous in the prior art is the connection of the thermoelectric elements to the fluid-conveying thermoelectric devices, particularly with respect to a lowest possible thermal resistance between the fluids and the thermoelectrically active materials. Disadvantageous in addition is the resistance to thermal stresses in the connecting material or the thermoelectric modules. Furthermore, the integratability of the thermoelectric modules in a device has not been optimally resolved thus far.